EP2176871B1 - Electromagnetic lifter for moving coils of hot-rolled steel and relevant operating method - Google Patents

Electromagnetic lifter for moving coils of hot-rolled steel and relevant operating method Download PDF

Info

Publication number
EP2176871B1
EP2176871B1 EP07827637.5A EP07827637A EP2176871B1 EP 2176871 B1 EP2176871 B1 EP 2176871B1 EP 07827637 A EP07827637 A EP 07827637A EP 2176871 B1 EP2176871 B1 EP 2176871B1
Authority
EP
European Patent Office
Prior art keywords
coil
check
hot
operating method
rolled steel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP07827637.5A
Other languages
German (de)
French (fr)
Other versions
EP2176871A1 (en
Inventor
Danilo Molteni
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SGM Gantry SpA
Original Assignee
SGM Gantry SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SGM Gantry SpA filed Critical SGM Gantry SpA
Publication of EP2176871A1 publication Critical patent/EP2176871A1/en
Application granted granted Critical
Publication of EP2176871B1 publication Critical patent/EP2176871B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/20—Electromagnets; Actuators including electromagnets without armatures
    • H01F7/206—Electromagnets for lifting, handling or transporting of magnetic pieces or material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C1/00—Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith for transmitting lifting forces to articles or groups of articles
    • B66C1/04—Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith for transmitting lifting forces to articles or groups of articles by magnetic means
    • B66C1/06—Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith for transmitting lifting forces to articles or groups of articles by magnetic means electromagnetic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/20—Electromagnets; Actuators including electromagnets without armatures
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S294/00—Handling: hand and hoist-line implements
    • Y10S294/907—Sensor controlled device

Definitions

  • the present invention relates to lifters used for moving coils of hot-rolled steel, and in particular to an electromagnetic lifter provided with a safety device.
  • coils of hot-rolled steel consist of a spiral-wound strip of electromagnetic sheet having a length up to 3000-3500 m and a weight ranging from 15 to 45 t, the spiral shape being maintained by a containment strapping.
  • a coil acts like a large spring whose external turns are subjected to a strong dynamism owing to the intrinsic elasticity of the system, whereby the coil can not be considered as an integral block.
  • the sheet is wound at high temperature (500-600°C and even more) and subsequently the coil is laid on the ground for the cooling phase.
  • the sheet gets shorter, its thickness gets smaller and the last turns are loaded with an energy that tends to move the sheet outwards. This happens because the natural shrinkage process can not take place completely since the coil is strapped with its turns tightly wound, and is laid on the ground or in anti-roll stalls at an horizontal axis position when it is still very hot.
  • lifters used to transport coils are mainly of the mechanical type in that they guarantee a safe lifting of the coil regardless of the deformed grip area and of the dynamism of the spiral structure.
  • electromagnetic lifters that are more efficient and faster than mechanical lifters yet they are affected by the above-mentioned particular characteristics of the coils of hot-rolled steel.
  • a standard electromagnetic lifter is suitable for the purpose as long as in the coils do not occur those mechanical dynamisms that may trigger magnetic dynamisms that lead to a reduction of the lifting force, up to the detachment of the load during transport, but this phenomenon is presently impossible to foresee with conventional lifters.
  • an electromagnet can compact the loosened turns of a coil in the region of its polar expansions, even merely through its own weight.
  • the magnetic flux linked between the electromagnet and the coil is sufficient to achieve an anchorage force greater than twice the coil weight, so that it suitable to lift and transport the coil according to the EN 13155 standard.
  • a flux meter possibly located in the close proximity of the polar expansions of said electromagnet would therefore detect during the transitory magnetization step a flux value and thus a magnetic induction value suitable to comply with said safety standard.
  • the problem of the electromagnetic lifter is that of detecting in the initial lifting step the elasticity of the turns affected by the magnetic field.
  • said mechanical dynamism can cause a more or less marked detachment of the external turns actually causing a decrease in the cross-sectional area of the flux lines, with consequent quadratic decrease in the anchorage force of the electromagnet that is proportional to the square of the induction.
  • This combined mechanical-magnetic effect between the coil and the electromagnet is defined hereafter “magnetic dynamism" for the sake of simplicity.
  • the problem may arise even if the magnetic dynamism occurs only at one of the polar expansions, since in said case the other polar expansion that generates a greater lifting force also generates a lever effect against the area of lower induction. This can trigger the accelerated loosening of the turns on the same side that already suffers from the magnetic dynamism, greatly increasing the probability of detachment of the coil.
  • the object of the present invention is to provide an electromagnetic lifter which is free from said drawbacks.
  • This object is achieved by means of an electromagnetic lifter comprising a safety device suitable to check in the initial lifting step the magnetic dynamism of each polar expansion as well as the overall magnetic dynamism of the lifter prior to authorizing the transport manoeuvre.
  • Other advantageous features of the present lifter are disclosed in the dependent claims.
  • the fundamental advantage of the present lifter stems from the fact that it can perform the transfer of hot-rolled steel coils in a condition of absolute safety, thus combining the practicality of electromagnetic lifters with the safety of mechanical lifters.
  • a second significant advantage results from the fact that said safety is obtained through a simple, inexpensive and reliable device.
  • an electromagnetic lifter conventionally includes two polar expansions 2, 3, shaped for transporting a horizontal axis coil 4, connected through a ferromagnetic circuit 5 and two cores 6, 7.
  • Two solenoids 8, 9 respectively arranged around said cores 6, 7 generate the magnetomotive force that allows to lift coil 4.
  • electromagnet 1 described here is preferably bipolar said choice is not binding, since magnets with different numbers of poles properly provided with the required devices can be manufactured by the same principle.
  • the novel aspect of the present lifter resides in the presence of two detection coils 10, 11, preferably of enamelled copper, respectively arranged around the cores 6, 7 close to the polar expansions 2, 3. Said coils 10, 11 are preferably protected by respective plates 12, 13 against the heat transmitted by coil 4 that in some cases is transported still hot.
  • Coils 10, 11 can detect the magnetic dynamism in the initial lifting step since they are crossed by the flux lines generated by solenoids 8, 9 and linked to coil 4, and therefore are capable of detecting the amount of the decrease of said linked flux lines (negative magnetic dynamism) caused by the mechanical dynamism of the turns of coil 4 when it is lifted.
  • This information is transmitted to two respective A/D converters 14, 15 that forward the data in digital format to a control unit 16 whose purpose is to grant or deny the authorization for transport.
  • Fa indicates the anchorage force of pole a (N pole in the example of Fig.2 )
  • Fb indicates the anchorage force of pole b (S pole in the example of Fig.2 )
  • Fsa and Fsa indicate the vertical lifting components of said anchorage forces
  • L1 and L2 indicate the lever arms measuring the distance between the barycentric axis of the load (P) and said vertical components Fsa and Fsb that hold half load (P/2) each.
  • Fig.4 shows a similar force system in condition of asymmetric magnetic dynamism, for example greater at pole b.
  • Fa>Fb Fa>Fb
  • Fsa>Fsb and Fsa*L1>Fsb*L2 whereby the lever effect against pole b can trigger the accelerated loosening of the turns on the same side greatly increasing the probability of load detachment.
  • the control unit 16 therefore performs a comparison of the magnetic dynamism occurring at the individual polarities on the basis of the data received from the detection coils 10, 11 through converters 14, 15. If the difference between the two values detected by coils 10, 11 exceeds a preset threshold that indicatively ranges from 3% to 10%, for example 5%, there is issued a signal for stopping the lifting operation and returning the load to the ground.
  • the control unit 16 checks that the overall magnetic dynamism of the system remains below the threshold set to authorize the transport, also in this case indicatively ranging from 3% to 10%. As a matter of fact, if the initial loosening of the turns remains within the parameters the phenomenon stops, whereby an overall decrease in the linked flux lower than, for example, another 5% allows to safely perform the transport. It should be noted that the safety and magnetic dynamism coefficients taken into consideration can be changed according to the needs of the case being considered.
  • the operating method of the electromagnetic lifter according to the present invention can therefore be summarized by the following steps:

Description

  • The present invention relates to lifters used for moving coils of hot-rolled steel, and in particular to an electromagnetic lifter provided with a safety device.
  • It is known that coils of hot-rolled steel consist of a spiral-wound strip of electromagnetic sheet having a length up to 3000-3500 m and a weight ranging from 15 to 45 t, the spiral shape being maintained by a containment strapping. Exactly due to this nature, a coil acts like a large spring whose external turns are subjected to a strong dynamism owing to the intrinsic elasticity of the system, whereby the coil can not be considered as an integral block.
  • These dynamic aspects occur in that the sheet is wound at high temperature (500-600°C and even more) and subsequently the coil is laid on the ground for the cooling phase. During said phase, the sheet gets shorter, its thickness gets smaller and the last turns are loaded with an energy that tends to move the sheet outwards. This happens because the natural shrinkage process can not take place completely since the coil is strapped with its turns tightly wound, and is laid on the ground or in anti-roll stalls at an horizontal axis position when it is still very hot.
  • The combination of these factors causes in the coil a loosening of the turns and a physical deformation concentrated in the coil portion facing upwards, and this deformed region coincides with the grip area by the lifter intended to transfer the coil. For this reason, lifters used to transport coils are mainly of the mechanical type in that they guarantee a safe lifting of the coil regardless of the deformed grip area and of the dynamism of the spiral structure.
  • However, it would be preferable to use electromagnetic lifters that are more efficient and faster than mechanical lifters yet they are affected by the above-mentioned particular characteristics of the coils of hot-rolled steel.
  • In fact, a standard electromagnetic lifter is suitable for the purpose as long as in the coils do not occur those mechanical dynamisms that may trigger magnetic dynamisms that lead to a reduction of the lifting force, up to the detachment of the load during transport, but this phenomenon is presently impossible to foresee with conventional lifters.
  • In the initial magnetization step an electromagnet can compact the loosened turns of a coil in the region of its polar expansions, even merely through its own weight. In this way, the magnetic flux linked between the electromagnet and the coil is sufficient to achieve an anchorage force greater than twice the coil weight, so that it suitable to lift and transport the coil according to the EN 13155 standard. A flux meter possibly located in the close proximity of the polar expansions of said electromagnet would therefore detect during the transitory magnetization step a flux value and thus a magnetic induction value suitable to comply with said safety standard.
  • The problem of the electromagnetic lifter is that of detecting in the initial lifting step the elasticity of the turns affected by the magnetic field. In fact said mechanical dynamism can cause a more or less marked detachment of the external turns actually causing a decrease in the cross-sectional area of the flux lines, with consequent quadratic decrease in the anchorage force of the electromagnet that is proportional to the square of the induction. This combined mechanical-magnetic effect between the coil and the electromagnet is defined hereafter "magnetic dynamism" for the sake of simplicity.
  • If this magnetic dynamism exceeds a critical threshold, it is very probable that the loosening of the steel turns of the coil will continue thus causing a further decrease in the linked flux lines. This can in turn trigger a chain reaction of further detachments and decreasing of flux lines up to making the lifting dangerous and not compliant with the EN 13155 standard, with the clear risk of load loss during the transport phase.
  • The problem may arise even if the magnetic dynamism occurs only at one of the polar expansions, since in said case the other polar expansion that generates a greater lifting force also generates a lever effect against the area of lower induction. This can trigger the accelerated loosening of the turns on the same side that already suffers from the magnetic dynamism, greatly increasing the probability of detachment of the coil.
  • Therefore the object of the present invention is to provide an electromagnetic lifter which is free from said drawbacks. This object is achieved by means of an electromagnetic lifter comprising a safety device suitable to check in the initial lifting step the magnetic dynamism of each polar expansion as well as the overall magnetic dynamism of the lifter prior to authorizing the transport manoeuvre. Other advantageous features of the present lifter are disclosed in the dependent claims.
  • The fundamental advantage of the present lifter stems from the fact that it can perform the transfer of hot-rolled steel coils in a condition of absolute safety, thus combining the practicality of electromagnetic lifters with the safety of mechanical lifters.
  • A second significant advantage results from the fact that said safety is obtained through a simple, inexpensive and reliable device.
  • Further advantages and characteristics of the lifter according to the present invention will be clear to those skilled in the art from the following detailed description of an embodiment thereof, with reference to the annexed drawings wherein:
    • Fig.1 is a diagrammatic front sectional view of a lifter according to the invention;
    • Fig.2 is a view similar to the preceding one that diagrammatically shows the operation of the lifter;
    • Fig:3 is a view similar to the preceding one that shows the force system in a condition of load engagement;
    • Fig.4 is a view similar to the preceding one that shows the force system in a condition of asymmetric magnetic dynamism; and
    • Fig.5 is a view similar to Fig.2 that diagrammatically shows the operation of the lifter in case of symmetric magnetic dynamism.
  • Referring first to Figs. 1-3, there is seen that an electromagnetic lifter according to the present invention conventionally includes two polar expansions 2, 3, shaped for transporting a horizontal axis coil 4, connected through a ferromagnetic circuit 5 and two cores 6, 7. Two solenoids 8, 9 respectively arranged around said cores 6, 7 generate the magnetomotive force that allows to lift coil 4. It should be noted that although electromagnet 1 described here is preferably bipolar said choice is not binding, since magnets with different numbers of poles properly provided with the required devices can be manufactured by the same principle.
  • The novel aspect of the present lifter resides in the presence of two detection coils 10, 11, preferably of enamelled copper, respectively arranged around the cores 6, 7 close to the polar expansions 2, 3. Said coils 10, 11 are preferably protected by respective plates 12, 13 against the heat transmitted by coil 4 that in some cases is transported still hot.
  • Coils 10, 11 can detect the magnetic dynamism in the initial lifting step since they are crossed by the flux lines generated by solenoids 8, 9 and linked to coil 4, and therefore are capable of detecting the amount of the decrease of said linked flux lines (negative magnetic dynamism) caused by the mechanical dynamism of the turns of coil 4 when it is lifted. This information is transmitted to two respective A/ D converters 14, 15 that forward the data in digital format to a control unit 16 whose purpose is to grant or deny the authorization for transport.
  • The operation of the present lifter is therefore quite simple and effective and is readily understood: the polar expansions 2, 3 contact coil 4 to be lifted and, upon activation of solenoids 8 and 9, the flux lines link to coil 4 as shown in Fig.2. At the beginning of the lifting step, in the absence of magnetic dynamism, the system balance condition is illustrated by the force system of Fig.3.
  • In said system, Fa indicates the anchorage force of pole a (N pole in the example of Fig.2), Fb indicates the anchorage force of pole b (S pole in the example of Fig.2), Fsa and Fsa indicate the vertical lifting components of said anchorage forces, L1 and L2 indicate the lever arms measuring the distance between the barycentric axis of the load (P) and said vertical components Fsa and Fsb that hold half load (P/2) each.
  • Fig.4 shows a similar force system in condition of asymmetric magnetic dynamism, for example greater at pole b. In such a case it is Fa>Fb, therefore also Fsa>Fsb and Fsa*L1>Fsb*L2 whereby the lever effect against pole b can trigger the accelerated loosening of the turns on the same side greatly increasing the probability of load detachment.
  • During the first lifting step, the control unit 16 therefore performs a comparison of the magnetic dynamism occurring at the individual polarities on the basis of the data received from the detection coils 10, 11 through converters 14, 15. If the difference between the two values detected by coils 10, 11 exceeds a preset threshold that indicatively ranges from 3% to 10%, for example 5%, there is issued a signal for stopping the lifting operation and returning the load to the ground.
  • On the contrary, a decrease in the linked flux that remains at a value below the alarm threshold does not trigger further detachments of sheet turns and blocks the magnetic dynamism, maintaining an anchorage force such that the transport can be made safely according to the provisions of the EN 13155 standard.
  • Where the two signals detected by coils 10, 11 are almost equivalent, as illustrated in Fig.5, in the immediately subsequent phase the control unit 16 checks that the overall magnetic dynamism of the system remains below the threshold set to authorize the transport, also in this case indicatively ranging from 3% to 10%. As a matter of fact, if the initial loosening of the turns remains within the parameters the phenomenon stops, whereby an overall decrease in the linked flux lower than, for example, another 5% allows to safely perform the transport. It should be noted that the safety and magnetic dynamism coefficients taken into consideration can be changed according to the needs of the case being considered.
  • The operating method of the electromagnetic lifter according to the present invention can therefore be summarized by the following steps:
    1. a) activating the magnetization solenoids 8, 9;
    2. b) checking that the flux linked to coil 4 to be transported is sufficient to achieve an anchorage force greater than twice the weight of coil 4;
    3. c) initially lifting coil 4 and simultaneously comparing the magnetic dynamism occurring at the individual polarities to check that the difference between the values detected by coils 10, 11 is below a preset threshold;
    4. d) in case of negative outcome of the check, issuing a signal for stopping the lifting operation and returning the load to the ground, and in case of positive outcome of the check performing a second check that the overall magnetic dynamism of the system is below a second preset threshold;
    5. e) in case of negative outcome of the second check, issuing a signal for stopping the lifting operation and returning the load to the ground, and in case of positive outcome of the check issuing a signal of authorization to the transport of coil 4.
  • It is clear that the above-described and illustrated embodiment of the lifter according to the invention is just an example susceptible of various modifications. In particular, converters 14, 15 could be integrated in control unit 16.

Claims (10)

  1. Electromagnetic lifter (1) comprising at least two polar expansions (2, 3) shaped for transporting a horizontal axis coil (4) of hot-rolled steel, said at least two polar expansions (2, 3) being connected through a ferromagnetic circuit (5) and respective cores (6, 7) around which two magnetization solenoids (8, 9) are arranged which when activated produce flux lines linking a horizontal axis coil (4) of hot-rolled steel to be transported, characterized in that it further includes at each of said cores (6, 7) a single detection coil (10, 11) arranged around said core (6, 7) and suitable to detect the change in the flux linked to said horizontal axis coil (4) of hot-rolled steel to be transported, as well as a control unit (16) operatively connected to said detection coils (10, 11) to compare the values detected by each detection coil (10, 11) in order to authorize or not the transport.
  2. Electromagnetic lifter according to claim 1, characterized in that each detection coil (10, 11) is arranged close to the relevant polar expansion (2, 3).
  3. Electromagnetic lifter according to claim 2, characterized in that the detection coil (10, 11) is made of enamelled copper.
  4. Electromagnetic lifter according to claim 2 or 3, characterized in that it further includes plates (12, 13) suitable to protect the detection coils (10, 11) from the heat transmitted by the coil (4) of hot-rolled steel.
  5. Electromagnetic lifter according to one of the preceding claims, characterized in that it includes A/D converters (14, 15) arranged between the detection coils (10, 11) and the control unit (16).
  6. Operating method for an electromagnetic lifter (1) according to one of the preceding claims, said method including the steps of:
    a) activating the magnetization solenoids (8, 9);
    b) checking that the flux linked to the coil (4) to be transported is sufficient to achieve an anchorage force greater than twice the weight of the coil (4);
    and being characterized in that it includes the further steps of:
    c) initially lifting the coil (4) and simultaneously checking that the difference between the values detected by the detection coils (10, 11) is below a preset threshold;
    d) performing or not a second check that the overall decrease of the linked flux is below a second preset threshold, depending on the outcome of said first check;
    e) issuing or not a signal of authorization to the transport depending on the outcome of said second check.
  7. Operating method according to claim 6, characterized in that if the first check of step c) has a negative outcome step d) provides the issue of a signal for stopping the lifting operation and returning the load to the ground.
  8. Operating method according to claim 6, characterized in that if the second check of step d) has a negative outcome step e) provides the issue of a signal for stopping the lifting operation and returning the load to the ground.
  9. Operating method according to claim 6, characterized in that the preset threshold for the first check of step c) indicatively ranges from 3% to 10%, preferably is 5%.
  10. Operating method according to claim 6, characterized in that the preset threshold for the second check of step d) indicatively ranges from 3% to 10%, preferably is 5%.
EP07827637.5A 2007-08-10 2007-08-10 Electromagnetic lifter for moving coils of hot-rolled steel and relevant operating method Active EP2176871B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/IT2007/000583 WO2009022357A1 (en) 2007-08-10 2007-08-10 Electromagnetic lifter for moving coils of hot-rolled steel and relevant operating method

Publications (2)

Publication Number Publication Date
EP2176871A1 EP2176871A1 (en) 2010-04-21
EP2176871B1 true EP2176871B1 (en) 2015-09-30

Family

ID=39267917

Family Applications (1)

Application Number Title Priority Date Filing Date
EP07827637.5A Active EP2176871B1 (en) 2007-08-10 2007-08-10 Electromagnetic lifter for moving coils of hot-rolled steel and relevant operating method

Country Status (8)

Country Link
US (1) US8210585B2 (en)
EP (1) EP2176871B1 (en)
JP (1) JP2010535682A (en)
KR (3) KR101524719B1 (en)
CN (1) CN101836271B (en)
BR (1) BRPI0721913A2 (en)
MX (1) MX2010001518A (en)
WO (1) WO2009022357A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101663649B1 (en) * 2009-09-01 2016-10-07 에스지엠 갠트리 에스.피.에이. Electromagnetic Lifter for moving Horizontal-Axis Coils and the Like
ITMI20122047A1 (en) * 2012-11-30 2014-05-31 Sgm Gantry Spa LIFT WITH ELECTROPERMANENT MAGNETS
EP3157854B1 (en) * 2014-06-20 2018-03-07 SGM Magnetics S.p.A. Electromagnetic lifter for hot materials
DE202017107536U1 (en) * 2017-12-11 2018-01-15 Bystronic Laser Ag Fastening device for machine tools and machine tool with a fastening device
CN108750904B (en) * 2018-08-23 2020-02-14 宝钢湛江钢铁有限公司 Electromagnetic lifting appliance for unmanned crane
CN109524194A (en) * 2018-12-04 2019-03-26 株洲悍威磁电科技有限公司 A kind of battery-type electricity permanent magnet and its forward and reverse exciting method

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3596967A (en) 1969-01-31 1971-08-03 United States Steel Corp Lifting device
US3783344A (en) 1972-01-05 1974-01-01 Sumitomo Heavy Industries Lifting magnet assembly
JPS574053Y2 (en) * 1978-03-09 1982-01-25
US4350379A (en) * 1980-10-10 1982-09-21 General Electric Company Universal lifting magnet
JPS63104387U (en) * 1986-12-23 1988-07-06
BR8702929A (en) * 1987-05-22 1988-12-20 Josef David Baumann PERMANENT MAGNETIC RETENTION DEVICE FOR MOVING MOUNTING OR TRANSPORT OF PIECES OR FERROMAGNETIC LOADS WITH ELECTRONIC SWITCHING OF THE MAGNETIC FLOW FOR DISCONNECTING TRANSPORTED LOAD
US5145227A (en) * 1990-12-31 1992-09-08 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Electromagnetic attachment mechanism
JP3440324B2 (en) * 1995-02-09 2003-08-25 三明電機株式会社 Two-sheet suction detection device
DE19531513C2 (en) * 1995-08-26 2002-06-20 Betr Forsch Inst Angew Forsch Electric lifting magnet
JPH10273278A (en) * 1997-03-28 1998-10-13 Shinko Electric Co Ltd Lifting electromagnet for high temperature steel product
JP2001502852A (en) 1997-08-04 2001-02-27 ライルフィクス エンヴェー Electromagnetic permanent magnet system type hoist with safety device
US6489871B1 (en) * 1999-12-11 2002-12-03 Simon C. Barton Magnetic workholding device
IT1319065B1 (en) * 2000-10-27 2003-09-23 Sgm Spa ELECTROMAGNET FOR HANDLING OF FERROMAGNETIC SCRAP
CN2561756Y (en) * 2002-07-24 2003-07-23 宝山钢铁股份有限公司 Maximum value indicator for electric magnets of crane
JP4607631B2 (en) * 2005-03-16 2011-01-05 株式会社日立製作所 Brake control device for elevator

Also Published As

Publication number Publication date
US8210585B2 (en) 2012-07-03
EP2176871A1 (en) 2010-04-21
CN101836271B (en) 2013-03-13
KR20140105851A (en) 2014-09-02
KR20150016289A (en) 2015-02-11
WO2009022357A1 (en) 2009-02-19
BRPI0721913A2 (en) 2014-02-25
JP2010535682A (en) 2010-11-25
US20110140468A1 (en) 2011-06-16
KR20100054825A (en) 2010-05-25
CN101836271A (en) 2010-09-15
KR101524719B1 (en) 2015-06-02
MX2010001518A (en) 2010-06-25

Similar Documents

Publication Publication Date Title
EP2176871B1 (en) Electromagnetic lifter for moving coils of hot-rolled steel and relevant operating method
US7692522B2 (en) Method and device for the safe operation of a switching device
JP2006014579A (en) System and method for protecting quench of superconductor
US20150291397A1 (en) Lifter with electropermanent magnets
US20080238217A1 (en) Fault-tolerant permanent magnet machine with reconfigurable flux paths in stator back iron
CN110235213A (en) Breaker
WO2011116488A1 (en) Method and apparatus for suppressing an inrush current of a trans former
CN107706890B (en) The line differential protection method and device of electric system
JP2008293337A (en) Coin sensor
CN110690690A (en) Current control apparatus
JP5828783B2 (en) DC circuit breaker
JP2009246162A (en) Superconducting coil device, method of detecting abnormal condition of superconducting coil and method of operating superconducting coil device
EP0715179A2 (en) Method for detecting full magnetisation of electropermanent magnets
JP6599907B2 (en) Electromagnetic lifter for high temperature materials
CA3000577A1 (en) Protection of power transformers
EP2136382A1 (en) Apparatus for automatic disconnection of current limiter
JP3585759B2 (en) Excitation inrush current discriminator
Kang et al. A novel CT saturation detecting algorithm unaffected by a remanent flux
JP4694133B2 (en) Interlock system of superconducting coil excitation demagnetization controller
WO2012013237A1 (en) Current limiter
JPH09142770A (en) Controller of lifting electromagnet
JPS63243765A (en) Current detector
JP2010016287A (en) High-temperature superconducting magnet system and operation method of the same
US20200135353A1 (en) Passive electrical component for safety system shutdown using faraday's law
JPH104011A (en) Non-inductive superconductive coil

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20100211

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA HR MK RS

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20130925

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

INTG Intention to grant announced

Effective date: 20150428

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 752847

Country of ref document: AT

Kind code of ref document: T

Effective date: 20151015

Ref country code: CH

Ref legal event code: NV

Representative=s name: RENTSCH PARTNER AG, CH

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602007043343

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20151231

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 752847

Country of ref document: AT

Kind code of ref document: T

Effective date: 20150930

REG Reference to a national code

Ref country code: NL

Ref legal event code: FP

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160130

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20160201

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602007043343

Country of ref document: DE

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

26N No opposition filed

Effective date: 20160701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160810

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160810

REG Reference to a national code

Ref country code: CH

Ref legal event code: PCAR

Free format text: NEW ADDRESS: BELLERIVESTRASSE 203 POSTFACH, 8034 ZUERICH (CH)

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20070810

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160831

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

REG Reference to a national code

Ref country code: CH

Ref legal event code: PFA

Owner name: SGM MAGNETICS S.P.A., IT

Free format text: FORMER OWNER: SGM GANTRY S.P.A., IT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150930

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 12

REG Reference to a national code

Ref country code: NL

Ref legal event code: HC

Owner name: SGM MAGNETICS S.P.A.; IT

Free format text: DETAILS ASSIGNMENT: CHANGE OF OWNER(S), CHANGE OF OWNER(S) NAME; FORMER OWNER NAME: SGM GANTRY S.P.A.

Effective date: 20180703

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: TR

Payment date: 20180704

Year of fee payment: 18

REG Reference to a national code

Ref country code: NL

Ref legal event code: MM

Effective date: 20190901

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20190810

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190901

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190810

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20210819

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20210819

Year of fee payment: 15

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602007043343

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20220831

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230301

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20230804

Year of fee payment: 17

Ref country code: CH

Payment date: 20230902

Year of fee payment: 17